M135/211 tanker (fire truck) with odd specs?

[zyewdall]

Wondering about the specs I'm seeing on this truck I'm looking at buying. Have not seen it in person yet -- maybe next weekend. But seller states a Chrysler Poly 318 engine with a manual transmission, and that it's a 1953 AM General, but from the looks, it's a M135 or M211 (can't sell for sure on the wheels whether they are dually or not on the back... they look like the width for dually, and if had a 1500 gallon water tank it should be dually, but body looks like the M135? ) Is is possible that someone replaced the original engine and transmission with something different? The poly 318 engine allegedly wasn't even made till 3 years after 1953.

https://www.facebook.com/marketplace/item/597015235696045/? has the full add with some pics (but none of the engine compartment).

How are these older trucks as off road/dirt road trucks? I used a M35A3 a lot in our volunteer fire department, and that was an awesome truck. It only had a 850 gallon tank though. And I would have preferred a manual transmission. This older one, whatever it is, would be for private use on our property in WA. Never need to go faster than maybe 20 mph (though it is roughly 80 miles to drive it home from the seller). But some steep dirt roads, around 28% grade max to go up. Pic of our departments M35A3 at work below.

 

[NDT]

That is a GMC, the wheels are the M211 type. Lots of mods on that one, the entire bed/tank is shop made, the cab top is shop made, the fuel tank is shop made. With the original automatic transmission gone, you have no low range for crawling. Probably all 12 volt converted. GMCs do just fine off road when stock, not sure about that one due to the manual transmission.